Net (device)
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Nets have been constructed by human beings since at least the
Mesolithic The Mesolithic ( Greek: μέσος, ''mesos'' 'middle' + λίθος, ''lithos'' 'stone') or Middle Stone Age is the Old World archaeological period between the Upper Paleolithic and the Neolithic. The term Epipaleolithic is often used synony ...
period for use in capturing or retaining things. Their open structure provide lightness and flexibility that allow them to be carried and manipulated with relative ease, making them valuable for methodical tasks such as hunting, fishing, sleeping, and carrying.


Definition

A net, in its primary meaning, comprises threads or yarns knotted and twisted into a grid-like structure which blocks the passage of large items, while letting small items and fluids pass. It requires less material than something sheet-like, and provides a degree of transparency, as well as flexibility and lightness.


History

The oldest nets found are from the
Mesolithic The Mesolithic ( Greek: μέσος, ''mesos'' 'middle' + λίθος, ''lithos'' 'stone') or Middle Stone Age is the Old World archaeological period between the Upper Paleolithic and the Neolithic. The term Epipaleolithic is often used synony ...
era, but nets may have existed in the Upper paleolithic era. Nets are typically made of perishable materials and leave little archeological record. Some nets are preserved in ice or bogs, and there are also clay impressions of nets.


Making and repairing nets

Originally, all nets were made by hand. Construction begins from a single point for round nets such as purse nets, net bags, or hair nets, but square nets are usually started from a headrope. A line is tied to the headrope at regular intervals, forming a series of loops. This can be done using slipped
overhand knot The overhand knot is one of the most fundamental knots, and it forms the basis of many others, including the Noose, simple noose, overhand loop, angler's loop, reef knot, fisherman's knot, Half hitch, and water knot. The overhand knot is a stopp ...
s or other knots, such as
clove hitch The clove hitch is a type of knot. Along with the bowline and the sheet bend, it is often considered one of the most important knots. A clove hitch is two successive Half hitch, half-hitches around an object. It is most effectively used as a cr ...
es. Subsequent rows are then worked using sheet bends, as shown in the diagram, or another knot. Some nets, such as hammocks, may be looped rather than knotted. To avoid hauling a long length of loose twine through each knot, the twine is wound onto a netting shuttle or netting needle. This must be done correctly to prevent it twisting as it is used,Netting instructions
/ref> but makes net production much faster. A gauge – often a smooth stick – is used to keep the loops the same size and the mesh even. The first and last rows are generally made using a half-size gauge, so that the edges of the net will be smooth. There are also knot-free nets. Some nets are still shaped by their end users,Net making
(and repair) guide for commercial fishing nets.
although nets are now often knotted by machine. When a hole is ripped in a net, there are fewer holes in it than before the net was ripped. However, the
stress concentration In solid mechanics, a stress concentration (also called a stress raiser or a stress riser) is a location in an object where the stress (mechanics), stress is significantly greater than the surrounding region. Stress concentrations occur when the ...
at the edges of the hole often causes it to tear further, making timely repairs important. Mending nets by hand is still an important skill for those who work with them.


Materials

Nets may be made using almost any sort of fiber. Traditional net materials varied with what was locally available; early European fishing nets were often made of linen, for instance. Longer-lasting synthetics are now fairly universal.
Nylon Nylon is a generic designation for a family of synthetic polymers composed of polyamides (polymer, repeating units linked by amide links).The polyamides may be aliphatic or Aromaticity, semi-aromatic. Nylon is a silk-like thermoplastic, genera ...
monofilament nets are transparent, and are therefore often used for fishing and trapping.


Structural properties

Nets, like fabric, stretch less along their constituent strands (the "bars" between knots) than diagonally across the gaps in the mesh. They are, so to speak, made on the bias. The choice of material used also affects the structural properties of the net. Nets are designed and constructed for their specific purpose by modifying the parameters of the weave and the material used. Safety nets, for example, must decelerate the person hitting them gradually, usually by having a concave-upwards
stress–strain curve In engineering and materials science, a stress–strain curve for a material gives the relationship between stress (mechanics), stress and Deformation (physics)#Strain, strain. It is obtained by gradually applying Structural load, load to a tes ...
, where the amount of force required to stretch the net increases the further the net is stretched.


Uses


Transport

Examples include
cargo net A cargo net is a type of net (device), net. It is usually square or rectangle, but sometimes round, made of thick rope, with cinch ropes extending from the corners, and in some designs, the edges. It is named for its use in transferring cargo t ...
s and net bags. Some vegetables, like onions, are often shipped in nets.


Sports

Nets are used in sporting goals and in games such as
soccer Association football, more commonly known as football or soccer, is a team sport played between two teams of 11 Football player, players who primarily use their feet to propel the Ball (association football), ball around a rectangular field ca ...
,
basketball Basketball is a team sport in which two teams, most commonly of five players each, opposing one another on a rectangular court, compete with the primary objective of shooting a basketball (approximately in diameter) through the defender' ...
, bossaball and
ice hockey Ice hockey (or simply hockey) is a team sport played on ice skates, usually on an Ice rink, ice skating rink with Ice hockey rink, lines and markings specific to the sport. It belongs to a family of sports called hockey. In ice hockey, two o ...
. A net separates opponents in various
net sports Net and wall games are pitch (sports field), court games where either a net (device), net separates the opponents or a wall serves to reflect the ball to the opponent. The object of these games is to hit the ball or Badminton#Shuttlecock, bird ov ...
such as
volleyball Volleyball is a team sport in which two teams of six players are separated by a net. Each team tries to score points by grounding a ball on the other team's court under organized rules. It has been a part of the official program of the Summe ...
,
tennis Tennis is a List of racket sports, racket sport that is played either individually against a single opponent (singles (tennis), singles) or between two teams of two players each (doubles (tennis), doubles). Each player uses a tennis racket th ...
,
badminton Badminton is a racquet sport played using racket (sports equipment), racquets to hit a shuttlecock across a net (device), net. Although it may be played with larger teams, the most common forms of the game are "singles" (with one player per s ...
, and
table tennis Table tennis, also known as ping-pong and whiff-whaff, is a sport in which two or four players hit a lightweight ball, also known as the ping-pong ball, back and forth across a table using small solid rackets. It takes place on a hard table div ...
, where the ball or shuttlecock must go over the net to remain in play. A net also may be used for safety during practice, as in
cricket Cricket is a Bat-and-ball games, bat-and-ball game played between two teams of eleven players on a cricket field, field at the centre of which is a cricket pitch, pitch with a wicket at each end, each comprising two Bail (cricket), bails b ...
.


Capturing animals

Nets for capturing animals include
fishing net A fishing net is a Net (device), net used for fishing. Nets are devices made from fibers woven in a grid-like structure. Some fishing nets are also called fish traps, for example #Fyke nets, fyke nets. Fishing nets are usually meshes formed by ...
s,
butterfly net A butterfly net (sometimes called an aerial insect net) is one of several kinds of Net (device), nets used to collect insects. The entire bag of the net is generally constructed from a lightweight mesh to minimize damage to delicate butterfly win ...
s, bird netting, and
trapping Animal trapping, or simply trapping or gin, is the use of a device to remotely catch an animal. Animals may be trapped for a variety of purposes, including food, the fur trade, hunting, pest control, and wildlife management. History Neolithic ...
nets such as purse and long nets. Some, like mist nets, rocket nets, and netguns, are designed not to harm the animals caught. Camouflage nets may also be used.


Furnishings

Hammock A hammock (from Spanish , borrowed from Taíno and Arawak ) is a sling made of fabric, rope, or netting, suspended between two or more points, used for swing (seat), swinging, sleeping, or Human relaxation, resting. It normally consists of one ...
s,
safety net A safety net is a net (device), net to protect people from injury after falling (accident), falling from heights by limiting the distance they fall, and deflecting to dissipate the impact energy. The term also refers to devices for arresting f ...
s, and mosquito nets are net-based. Some furniture includes a net stretched on a frame. Multihull boats may have net trampolines strung between their hulls.


Clothing

Hair nets, net lace, and net embroidery are sartorial nets.


Armed conflict

Anti-submarine nets and anti-torpedo nets can be laid by net-laying ships.


See also

Net (textile) Net or netting is any textile in which the yarns are fused, looped or knotted at their intersections, resulting in a fabric with open spaces between the yarns. Net has many uses, and comes in different varieties. Depending on the type of yarn or ...


References

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